1. Field of the Invention
The present invention relates to a control apparatus for an internal combustion engine, and particularly, to a control apparatus for an internal combustion engine having a reverse rotation detecting function of the internal combustion engine.
2. Description of Related Art
When ignition is made before a compression top dead center in a case where the rotational speed of a crankshaft is insufficient at the startup (cranking) of an internal combustion engine by manual operation, a phenomenon, so-called rebounding of kick pedal in which the crankshaft makes reverse rotation and a reverse rotation load is applied to manual starting operation devices (e.g., kick arm) may occur.
As techniques for preventing such rebounding of kick pedal, techniques mentioned in the following (1) and (2) are conventionally known.
(1) As disclosed in Japanese Patent No. 2780257, in an ignition device that performs ignition output according to an output voltage signal of a crank angle position detecting timing sensor (crank sensor), when the ignition device detects that an output voltage signal of a predetermined phase of the crank sensor does not coincide with an output voltage of one of the predetermined phases of a magnet-type AC generator that rotates in synchronization with a crankshaft, ignition output is stopped.(2) As disclosed in Japanese Patent No. 3125587, in an ignition device that has a power source coil exclusive for ignition (so-called exciter coil) that is packaged in a magnet-type AC generator, the power source coil outputs an alternating voltage with a plurality of cycles per one revolution in synchronization with the rotation of a crankshaft, the ignition device causes ignition output to be stopped according to an output voltage of an exciter coil with a predetermined phase.
In the above conventional techniques, when a failure (e.g., a case where the magnet-type AC generator (including the exciter coil) to be used for detection of reverse rotation is disconnected, or is short-circuited from other power sources such a multiphase generator or a battery) has occurred, the reverse rotation cannot be detected, and it is impossible to prevent rebounding of kick pedal.
Furthermore, the above-described failure has occurred, it is not possible to determine that the internal combustion engine makes forward rotation or reverse rotation. Therefore, if startup of an internal combustion engine is impossible or the engine is under operation, an engine stall will occur.
Conventionally, since a technique of detecting a failure of the magnet-type AC generator to be used for detection of reverse rotation is not suggested, when a failure has occurred in such a magnet-type AC generator, there are problems in that rebounding of kick pedal cannot be prevented, startup of the engine is not possible, or, if the engine is under operation, an engine stall may occur.